The overall objective of this project is to determine the molecular basis for the specific interaction of nerve and muscle. In the coming year further studies of the previously described nevous system specific band 1 protein will attempt to firmly establish the relationship between the high and low molecular weight forms of this polypeptide. Band 1 will be isolated in quantity and monoclonal antisera to it produced. The potential interaction of band 1 with primary muscle cultures and also other cultured cells will be examined. In addition, the interaction of cell surface components of other neuronal cells with cultured muscle cells will be examined. The neuronal cells will include the PC12 pheochromocytoma and NG108 neuroblastoma/glioma hybrid cell line (both capable of forming synapses) and also primary cultures of mouse and rat brain. Neuronal components which bind to muscle cultures will be analyzed on SDS polyacrylamide gels. Purification of components which bind specificaly to muscle will be initiated.